Marlaina R Stocco, Mari Purpura, Philip A Vieira, Kira Wallquist, Sijia Wang, Julia Adams, Karen K Szumlinski, Tod E Kippin
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引用次数: 0
Abstract
Rationale: A central component of substance use disorder is the maladaptive choice of the drug over natural reinforcers. Compared to other drugs of abuse, methamphetamine (METH) choice has received limited study.
Objective: We sought to characterize the role of intertrial interval on METH choice behavior.
Methods: We examined the choice of METH versus food, across multiple METH doses (0.05-0.2 mg/kg/infusion), between male and female rats, employing a fixed ratio (FR1) reinforcement schedule with intertrial intervals (ITIs) of 20 and 600 s. Rats learned to lever-press for either the METH or the food reinforcer during separate, alternating training sessions. Rats then underwent choice testing, where both levers were presented for 25 discreet trials per session. Lastly, under a progressive ratio (PR) schedule, breakpoints for METH and food were assessed during separate, alternating sessions.
Results: METH choice was substantially higher when using the 20 s versus 600 s ITI. When the 20 s ITI was used, choice was dose- but not sex-dependent. When using the 600 s ITI, choice was influenced by dose and sex, with female rats in the higher dose group choosing METH more than other groups. PR breakpoints were higher for METH than for food, and this effect was more pronounced among female rats. METH choice was positively correlated with the ratio of METH/food breakpoints.
Conclusion: Reinforcement schedule parameters, namely ITI, during discrete choice testing can markedly influence METH choice behavior; thus, this should be carefully considered during experiment design and selected based on overarching study aims.
期刊介绍:
Official Journal of the European Behavioural Pharmacology Society (EBPS)
Psychopharmacology is an international journal that covers the broad topic of elucidating mechanisms by which drugs affect behavior. The scope of the journal encompasses the following fields:
Human Psychopharmacology: Experimental
This section includes manuscripts describing the effects of drugs on mood, behavior, cognition and physiology in humans. The journal encourages submissions that involve brain imaging, genetics, neuroendocrinology, and developmental topics. Usually manuscripts in this section describe studies conducted under controlled conditions, but occasionally descriptive or observational studies are also considered.
Human Psychopharmacology: Clinical and Translational
This section comprises studies addressing the broad intersection of drugs and psychiatric illness. This includes not only clinical trials and studies of drug usage and metabolism, drug surveillance, and pharmacoepidemiology, but also work utilizing the entire range of clinically relevant methodologies, including neuroimaging, pharmacogenetics, cognitive science, biomarkers, and others. Work directed toward the translation of preclinical to clinical knowledge is especially encouraged. The key feature of submissions to this section is that they involve a focus on clinical aspects.
Preclinical psychopharmacology: Behavioral and Neural
This section considers reports on the effects of compounds with defined chemical structures on any aspect of behavior, in particular when correlated with neurochemical effects, in species other than humans. Manuscripts containing neuroscientific techniques in combination with behavior are welcome. We encourage reports of studies that provide insight into the mechanisms of drug action, at the behavioral and molecular levels.
Preclinical Psychopharmacology: Translational
This section considers manuscripts that enhance the confidence in a central mechanism that could be of therapeutic value for psychiatric or neurological patients, using disease-relevant preclinical models and tests, or that report on preclinical manipulations and challenges that have the potential to be translated to the clinic. Studies aiming at the refinement of preclinical models based upon clinical findings (back-translation) will also be considered. The journal particularly encourages submissions that integrate measures of target tissue exposure, activity on the molecular target and/or modulation of the targeted biochemical pathways.
Preclinical Psychopharmacology: Molecular, Genetic and Epigenetic
This section focuses on the molecular and cellular actions of neuropharmacological agents / drugs, and the identification / validation of drug targets affecting the CNS in health and disease. We particularly encourage studies that provide insight into the mechanisms of drug action at the molecular level. Manuscripts containing evidence for genetic or epigenetic effects on neurochemistry or behavior are welcome.